A RECONSTRUCTION by Portuguese detectives of key events on the day Madeleine McCann went missing has helped persuade the country's legal offi-cials to re-open the case, we reveal today.

The detectives, who have been reviewing the case files for two years, went to Praia da Luz on the Algarve a month ago to pursue secret inquiries.

They spent hours walking around the Ocean Club working out where certain people were seen at particular times and at Apartment 5a, from where threeyear-old Madeleine went missing on May 3, 2007.

The exercise was the culmination of months of work by four Portuguese detectives based in Porto in the north of the country, who are directly working for the highly respected senior officer Helen Monteiro, an expert on abduction cases.

It is thought her elite team of dedicated officers has recently been concentrating on statements from witnesses who say they saw unknown people acting suspiciously in the resort around the time the child was missed. The work in Luz came before Scotland Yard released photofits of potential suspects on the BBC's Crimewatch show this month.

Madeleine McCann went missing from this apartment in 2007 [EXPRESS NEWSPAPERS]

Often there are almost perfect crimes and not all of them are discovered all over the world

Paula Teixeira da Cruz, Portuguese Justice Minister

Ms Monteiro has insisted all her officers work in absolute secrecy to prevent leaks of their inquiries. It was decided officers in Porto should conduct the review as none had any direct involvement in the first Madeleine McCann investigation and would therefore approach the case with fresh eyes and open minds.

In Portugal, Ms Monteiro is seen as the driving force finally to get the Madeleine case files re-opened after five years, rather than through the efforts of Scotland Yard. She and her team are working separately from the Yard, although there is close liaison between the two.

Yesterday Portuguese Justice Minister Paula Teixeira da Cruz said the decision to reopen the case, taken last week, was due to the work of the Policia Judiciaria and not because of pressure from Scotland Yard. She said: "The PJ developed diligences that allowed for this process to be reopened. Often there are almost perfect crimes and not all of them are discovered all over the world. If the PJ requested the reopening, it has good motives to do so."

Portuguese law officials and senior officers in the PJ have been acutely aware of criticism of the initial police investigation and insist they are determined to solve the case.

The McCann's Portugese lawyer Rogerio Alves wants the parents to act as 'assistants' in the case [AFP]

Ms Teixeira da Cruz urged people to be "proud" of the work being done by the PJ, which she insisted had not been idle in seeking to solve the mystery.

For a time Madeleine's parents, Kate and Gerry McCann, were seen as arguidos or suspects but that status was lifted. Now they are being kept fully informed of all developments and were given a personal briefing of the work of the PJ in Lisbon last week.

The McCann's Portuguese lawyer, Rogerio Alves, is reportedly seeking for his clients to be "assistants" in the case. This would allow their lawyer to work closely with state prosecutors.